Convert Grains to Ounces
1 grain is 0.002286 oz. One grain is exactly 0.00228571428571 ounces.
One grain is 0.0022857143 ounces. To convert grains to ounces, multiply by 0.0022857143; to go the other way, divide by 0.0022857143 or multiply by 437.5. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST Handbook 44. Exactly 64.79891 milligrams, the unit both the avoirdupois and troy systems are built from.
Factor checked against the defining standard · How we check
- Grains × 0.0022857143
1 * 0.00228570.002 oz
1 grain in every weight unit
| Unit | Value | Exact factor |
|---|---|---|
| ounces | 0.002285714286 oz | × 0.00228571428571 |
| pounds | 0.0001428571429 lb | × 0.000142857142857 |
| stone | 0.00001020408163 st | × 0.0000102040816327 |
| US tons | 0.00000007142857143 ton | × 0.0000000714285714286 |
| micrograms | 64,798.91 mcg | × 64,798.91 |
| milligrams | 64.79891 mg | × 64.79891 |
| centigrams | 6.479891 cg | × 6.479891 |
| grams | 0.06479891 g | × 0.06479891 |
| kilograms | 0.00006479891 kg | × 0.00006479891 |
| slugs | 0.000004440135739 slug | × 0.0000044401357388 |
| tonnes | 0.00000006479891 t | × 0.00000006479891 |
| carats | 0.32399455 ct | × 0.32399455 |
| troy ounces | 0.002083333333 ozt | × 0.00208333333333 |
| grains (as entered) | 1 gr | — |
| long tons | 0.0000000637755102 LT | × 0.0000000637755102041 |
Factors are entered by hand from NIST Handbook 44 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert grains to ounces? The converter and the working
- 1.Take the measurement in grains.
- 2.Multiply by 0.0022857143 — that is how many ounces fit in one grain.
- 3.To go back the other way, divide by 0.0022857143, or multiply by 437.5.
Worked example: 25 grains to ounces
- Formula
- gr × 0.0022857143 = oz
- Arithmetic
- 25 × 0.0022857143 = 0.06 oz
- Answer
- 25 gr = 0.06 oz
The factor is rounded for display; the figure above is computed from the full value.
Grains to ounces conversion table
| Grains | Ounces |
|---|---|
| 1 gr | 0.002286 oz |
| 2 gr | 0.004571 oz |
| 3 gr | 0.01 oz |
| 4 gr | 0.01 oz |
| 5 gr | 0.01 oz |
| 6 gr | 0.01 oz |
| 7 gr | 0.02 oz |
| 8 gr | 0.02 oz |
| 9 gr | 0.02 oz |
| 10 gr | 0.02 oz |
| 12 gr | 0.03 oz |
| 15 gr | 0.03 oz |
| 20 gr | 0.05 oz |
| 25 gr | 0.06 oz |
| 50 gr | 0.11 oz |
| 100 gr | 0.23 oz |
| 200 gr | 0.46 oz |
| 300 gr | 0.69 oz |
| 500 gr | 1.14 oz |
| 1000 gr | 2.29 oz |
| 2000 gr | 4.57 oz |
| 5000 gr | 11.43 oz |
| 10000 gr | 22.86 oz |
What is a grain?
Exactly 64.79891 milligrams, the unit both the avoirdupois and troy systems are built from. Bullet weights and powder charges are still measured in it, and so are some pharmaceutical doses.
What is an ounce?
One sixteenth of a pound. Not to be confused with the fluid ounce, which measures volume.
How many ounces are in a grain?
One grain is 0.0022857143 ounces. Going the other way, one ounce is 437.5 grains. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every weight unit here
The whole group — 15 units with their symbols and the size of each one in kilograms — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a grain.
Cite this page
- APA
- Rule Calculator. (2026). Convert Grains to ounces. Rule Calculator. https://rulecalculators.com/convert/grain-to-ounce
- MLA
- "Convert Grains to ounces." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/grain-to-ounce.
- Chicago
- Rule Calculator. "Convert Grains to ounces." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/grain-to-ounce.
The date is when the figures on this page were last checked against their source, not the day you opened it. Add your own access date if your style needs one.
Questions people actually ask
- How many ounces are in a grain?
- 0.0022857143. One sixteenth of a pound. Not to be confused with the fluid ounce, which measures volume.
- How do I convert ounces back to grains?
- Divide by 0.0022857143, or multiply by 437.5 — they are the same operation.
Other weight conversions
Ounces to grains — the same conversion the other way.